Calipers are used to make accurate measurements between points. Vernier calipers differ from the basic caliper in that they have scales of measurement on the tool. This means that you can quickly determine the measurement. Vernier calipers are intended for fine measurements and generally measure to with .001 of an inch.
Calipers have been used since ancient times. A caliper can be locked to hold a measurement of a given item and used as the template to determine that a new or duplicate item is the same size. Invention of the Vernier caliper is credited to Pierre Vernier, a French scientist and mathematician .
The primary benefit of the vernier caliper is that it has scales of measurement built into the tool. A fixed scale and a sliding scale are utilized to determine measurements to within .001 inches. Also, unlike most calipers, Vernier calipers can be used in a number of ways. One set of measurement jaws can be used to determine outer measurements while another set of jaws can be used for interior measurements. Additionally, a sliding bar at the rear of the tool can be used to determine depth measurements.
Variations to the Vernier caliper make its use even simpler. Dial calipers are a type of Vernier caliper in which a dial serves as the smaller scale (reading measurements within .099 inches). Even more accurate in reading are the digital Vernier calipers. These utilize a digital display to give a reading and can be quickly switched between standard and metric dimensions.